Cylinder cooling system



Dec 14, 1937. G. A. SPELTS CYLINDER COOLING SYSTEM Filed Nov. 20, 1935 HGZ )ZIyIENTOR JW A TTORNEYS.

Patented Dec. 14, 1937 PATENT o FicE CYLINDER COOLING SYSTEM George Allen Spe1ts, Los Angeles, Calif., assignmof seven percent to W. F. Arndt and thirty percent to L. J. Styskal, both of county of Los Angeles, Calif.

Application November 20, 1935, Serial No. 50,757

, 5 Claims. '(01. 123-173 My invention relates to internal combustion engines ingeneral, and particularly to cooling systems for cooling the cylinder walls and cylinder head of two stroke cycle engines.

It is the general practice to cool such engines by urging cooling water to enter the water jacket at some point on the lower portion of the water jacket, and to allow said water to emerge at some point on. theupper portion of the water jacket. Some of the waterwill thus circulate through the cylinder head, some of it will only travel around the cylinder and emerge. Very little of it will circulate around the exhaust bridges and consequently, such bridges become overheated and often burn and pit badly.

One method of overcoming such burning and pitting has been to provide a separate orifice through which a jet of cooling'water impinges upon the exhaust bridges. While this method does cool the-bridges more than is generally the practice, it complicates the system as a separate source of water under pressure must be available.

Another undesirable feature of cooling cylinders as generally practiced is thatthe' cylinder and heads are of uneven temperature due to erratic paths taken by the cooling water. As a consequence cylindersoften warp and unsatisfactory performance results.

It is therefore an object of my invention to provide means for cooling the exhaust bridges and 'po'rt'of two cycle engines to such a degree as to prevent burning, scoring, or pitting. of the same.

It is also an object of my invention to provide means for cooling the cylinder walls and head uniformly, thus preventing warping of the same.

My invention possesses many other advantages and has other objects which may be more easily apparent from a consideration of one embodiment of my invention. For this purpose I have shown one form of my invention in conjunction with a two stroke cycle internal combustion engine. I shall now proceed to describe this form in detail, which illustrates the general principles of my invention, but it is to be understood that this description is not to be taken in a limiting sense, since the scope of my invention is best defined in the subjoined claims.

.In the drawing:

Figure 1 represents a cut-away view of a cylinder and head of a two cycle engine. I have not shown any non-essential parts (as far as my cooling system. is concerned) such as intake, spark plug, piston, etc., for the sake of clarity.

Figure 2 represents a cross-section of my cylinder and water jacket taken through plane A A tail, I show a cylinder I, attached to engine frame 2, and having a cylinder head 3 attached. I show cylinder walls 4 surrounded by an outer shell 5, each having cooperating passages defining exhaust ports 5. I also provide exhaust bridges I having open cores through which cool-v ing water may pass.

Cylinder walls 4 and shell 5 define in general a water jacket 8. To the right of the exhaust bridges, I provide a semi-circular obstructional web 9 between cylinder walls 4 and shell 5. I

also provide two diversion ribs It between cylinder walls 4 and shell 5, extending from the cylin'der head end to the web 9. Ribs l8 and web 9 thus divide'the water jacket intothree distinct parts, namely, an upper portion l2 extending along the upper half of the cylinder from the head toweb 9, a lower portion extending from the head as far along the lower half of the cylinder as ribs Ill, and a third portion l3 entirely surrounding the cylinder to the right of web 9. V

In addition I provide a'web 9 -A similar to web 9 but positioned just to the "right and con tiguous to the exhaust bridges. Now if water is urged to enter at waterinlet I5, all of said water will pass through the cores of exhaust bridges 1, thus cooling said bridges very effectively.

Small openings ll, one on each side of the exhaust bridges, maybe provided in web 9A, by-passing a small portion of the cooling water to aid in even cooling of the cylinder walls further'away from the exhaust port. Most of the water however flows through the cores of bridges 1.

Substantially the same results could be obtained by means of a conduit or series of conduits connecting to the cores of bridges 1. Such conduit or conduits may then be considered as a, closed portion from which cooling water can exit through the cores of the exhaust bridges.

This water is heated as it passes through said cores. The same water is further heated as it circulates through upper half l2 of water jacket 8, the head 3, and lower half I3 01' the water jacket, but said heating is of the order of relatively few degrees, and thus it keeps the cylinder at a relatively constant temperature along its length. Thus warping is definitely suspended. Furthermore, the rear or right hand end of the cylinder is warmed up to approximately the same temperature the firing end of the cylinder and head operate at. The water may exit through exhaust ports Hi.

It is now clear that the bridges operate at a temperature sufliciently low to prevent burning of the same, by virtue of the coldest cooling water flowing through the bridge cores first. Thus the hottest part of the engine is cooled by the coldest water, the coldest part of the engine by the warmest water, while the normally hot parts such as the cylinder walls at the firing end and the head are held down to an efficient temperature.

Engines thus cooled can be and are being operated so that ones hand can be touched to any part of the engine for a considerable time before the heat makes one recoil. Before such system was installed, the same engine could not be touched without blistering the skin.

This system does away with all hot spots as a definite circulation of all the Water is secured through all essential parts such as the exhaust ports and the. cylinder head.

Having described my invention, I claim:

1. In a two cycle engine, the combination comprising a cylinder having a shell forming a water jacket surrounding the cylinder, and having two longitudinal ribs extending along the cylinder periphery between the cylinder and the shell, said ribs dividing the space between the cylinder and the shell into two parts, a cylinder head having water passages forming a connection between the two water jacket parts, and means for circulating water from one part through the head to the other part, including an inlet in one part and an outlet in the other part.

2. In a cooling system of a two cycle engine having exhaust bridges, the combination comprising a cylinder having a shell forming a water jacket surrounding the cylinder, the exhaust bridges being provided with water passages, webs forming an enclosed part of the water jacket adjacent to the exhaust bridges, and an inlet provided in the shell for the passage of cooling water, the cores of the exhaust bridges forming the outlet of the cooling water from said enclosed part into the remainder of the cooling system.

3. In a, cooling system of a two cycle engine having exhaust bridges provided with cores for the passage of cooling water therethrough, a cylinder, a shell around the cylinder and forming a water cooling space between the cylinder and the shell, two ribs each extending longitudinally between the shell and the cylinder from the cylinder head to a plane beyond the exhaust bridges, a, semi-circular web between the shell and the cylinder and situated at the end of the ribs, a 1,

second semi-circular web provided with openings corresponding to the exhaust bridge cores and being adjacent the exhaust bridges, said webs and that part of the ribs between the planes of the webs forming an enclosed portion of the Water space with the exception of the exhaust bridge cores, a. water inlet provided in the shell for entrance of cooling water into the enclosed portion, and. a water outlet in the shell situated still further from the cylinder head than the first mentioned web.

4. In a cooling system of a two cycle engine having exhaust ports and bridges, the combination comprising a cylinder having a shell forming a water jacket substantially surrounding the cylinder, the exhaust bridges being provided with water passages, means forming an enclosed portion of the water jacket adjacent to the exhaust bridges, the water passages in said exhaust bridges forming an outlet from the enclosed portion, means for water entrance into the enclosed portion, means for guiding the water passing out of the enclosed portion along a portion of the cylinder periphery, through the cylinder head and back along the remainder of the cylinder periphery, and water outlet means.

5. In a cooling system of a two cycle engine having exhaust ports and exhaust bridges provided with cores for the passage of cooling water therethrough, a cylinder, a shell substantially surrounding the cylinder and forming a water jacket therewith, two ribs each extending longitudinally between the shell and the cylinder and dividing the water jacket between the cylinder head and the exhaust ports into two parts, means for causing substantially all the cooling water to pass through the cores and into one part of the jacket, means in the cylinder head for causing the water to flow back into the other part of the jacket and causing water to exit from the part of the water jacket not divided into two parts.

GEORGE ALLEN SPELTS. 

